sedimentary
Limonite Concretion
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH2O
AI-generated identification · may be incorrectHardness ranges from 4 to 5.5 on the Mohs scale. Colors are typically yellowish-brown, brown, or dark brown with a yellowish-brown streak and submetallic to earthy luster.
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Physical properties
Hardness ranges from 4 to 5.5 on the Mohs scale. Colors are typically yellowish-brown, brown, or dark brown with a yellowish-brown streak and submetallic to earthy luster.
Formation & geological history
Formed through the low-temperature oxidation and weathering of iron-rich minerals and rocks in sedimentary environments.
Uses & applications
Historically used as a pigment for paints and a low-grade iron ore. Highly sought after by mineral collectors for unusual botryoidal or concretionary shapes.
Geological facts
Also known as brown iron ore, limonite is not a distinct mineral species but rather a mixture of related hydrated iron oxides, primarily goethite and lepidocrocite.
Field identification & locations
Easily identified in the field by its characteristic yellowish-brown streak and brownish concretionary form. Found worldwide in weathered iron deposits.
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